The meetings are part of a visit to the US to learn about the work of specialist agencies in preventing child trafficking and sexual abuse.

Gerry McCann Visiting Washington DC, July 23-27, 2007

Mr McCann and his wife Kate, from Rothley, Leicestershire, have mounted a vigorous campaign to find four-year-old Madeleine since she disappeared from a holiday apartment in Praia da Luz, Portugal, on May 3.

He has also met experts from the National and International Centres for Missing and Exploited Children in the US.

Mr McCann said: “Obviously my focus just now is on trying to get our daughter back. That’s the key thing.

“But I think there is a lot of goodwill out there at the minute, that we might be able to leave something tangible for all children, and I think most people agree that these sorts of crimes should not happen and the perpetrators have to be pursued wherever these crimes are performed.

“She knows very much that we love her and we won’t stop searching for her.”

Mrs McCann remains in Portugal with the couple’s two-year-old twins, Sean and Amelie.

Meanwhile, posters of Madeleine are being displayed at booksellers in more than 200 countries around the world thanks to Harry Potter author JK Rowling, whose final instalment of the boy wizard’s adventures was published on Saturday.